Rotary transformers are used in catheter systems to couple electrical signals between rotating and non-rotating components of the catheter systems. For example, a catheter system may comprise a rotatable transducer received within a catheter body. The transducer is attached to the distal end of a drive cable that is driven by a motor to rotate the transducer within the catheter body. In this example, a rotary transformer may be used to couple electrical signals between the rotating transducer and stationary electronics.
A rotary transformer typically comprises two ferrite cores, in which one of the cores rotates relative to the other core. A primary winding is wound around one core and a secondary windings is wound around the other core. The two cores provide magnetic coupling between the two windings, thereby coupling electrical signals from one winding to the other winding.
A problem with existing rotary transformers is that their magnetic coupling degrades at high frequencies. This causes the amplitude of signals coupled through the rotary transformer to roll off at high frequencies, thereby limiting the bandwidth of the rotary transformer.
Therefore, there is a need for rotary transformers that are able to couple signals at higher frequencies. There is also a need for rotary transformers having wider bandwidths.